With the increased concern about environmental quality, there is a need for new technology to greatly reduce nitrogen oxide, carbon monoxide, hydrocarbon and particulate emissions from land based vehicles such as buses, trucks, automobiles and locomotives. Further, the increasingly tight emissions control standards, rising fuel costs, and limited land availability argue for new approaches for decentralized power generation systems. In both stationary and mobile applications, there is also a need for increased efficiency as compared to currently existing vehicles and power generating stations.
Fuel cells which have been developed in order to directly convert chemical energy into electricity have found applications in a variety of areas such as power sources on spacecraft. See, Patil, P. G., J. of Power Sources Vol. 37, 171 (1992). Fuel cells offer the advantages of low atmospheric pollution, high efficiency (up to 60%), compactness and modularity. In a fuel cell, hydrogen-rich gas and oxygen, typically from air, flow through porous electrodes and create electric current as the chemical reactions release electrons at one electrode and absorb them at the other. Some fuel cells require very pure hydrogen gas while others can tolerate significant amounts of other species. A major factor in utilization of fuel cells is the source of hydrogen-rich gas. High temperature fuel cells (molten carbonate at 650.degree. C. and solid oxide at 1000.degree. C.) can produce the required hydrogen-rich gas from natural gas and methanol inside the fuel cell directly (internal reforming) without the need of an external processing unit (a reformer) to turn hydrocarbon fuels into hydrogen-rich gas; but natural gas is difficult to supply to certain locations and its use in vehicles has the problems of storage, and it requires the development of a new distribution system. Methanol is toxic, corrosive and has similar distribution problems that natural gas does. Moreover, the internal reforming of the light and heavy hydrocarbons in natural gas within the inlet manifolds and inside of the fuel cell can cause carbon deposition and the attendant plugging problems. The required hydrogen-rich gas can also be obtained from external catalytic reformers which are relatively expensive and large. Further, such reformers need special handling and require the combustion of fossil fuel for heating the reformer. In addition, the range of hydrocarbon fuels that could be processed by these reformers is limited.
Plasmatrons or plasma reformers are devices which employ an electric discharge in order to produce, for example, reducing gases including hydrogen from hydrocarbons. See, for example, Kerker, L., "Manufacture of Gaseous Reductants and Synthesis Gas using Arc Plasma Processes," Elektrowaerme International, Edition B, vol. 45, no. 3-4, p. 155-61 (1987). A particular water plasmatron is disclosed in USSR Patent No. 700935, August 1979 by A. Rabinovich, one of the inventors herein. See also, Kaske, G. et. al., "Hydrogen Production by the Hulls Plasma-Reforming Process," Adv. Hydrogen Energy, Vol. 5, (1986).